.\"-
.\" SPDX-License-Identifier: 0BSD
.\"
.\" Copyright (c) 2016 genua mbH
.\"
.\" Permission to use, copy, modify, and distribute this software for any
.\" purpose with or without fee is hereby granted, provided that the above
.\" copyright notice and this permission notice appear in all copies.
.\"
.\" THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
.\" WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
.\" MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
.\" ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
.\" WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
.\" ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
.\" OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
.\"
.\" $NetBSD: umb.4,v 1.4 2019/08/30 09:22:17 wiz Exp $
.\"
.Dd September 3, 2025
.Dt UMB 4
.Os
.Sh NAME
.Nm umb
.Nd USB Mobile Broadband Interface Model (MBIM) cellular modem driver
.Sh SYNOPSIS
.Cd "device usb"
.Cd "device umb"
.Pp
In
.Xr loader.conf 5 :
.Cd umb_load="YES"
.Sh DESCRIPTION
The
.Nm
driver provides support for USB MBIM devices.
If the appropriate hardware is detected,
the driver will be loaded automatically by
.Xr devmatch 8 .
To load the driver manually,
.Cm load
it in
.Xr loader.conf 5
or at the
.Xr loader 8
prompt.
.Pp
MBIM devices establish connections via cellular networks such as
GPRS, UMTS, and LTE.
They appear as a regular point-to-point network interface,
transporting raw IP frames.
.Pp
Required configuration parameters like PIN and APN have to be set
with
.Xr umbctl 8 .
Once the SIM card has been unlocked with the correct PIN, it
will remain in this state until the MBIM device is power-cycled.
In case the device is connected to an "always-on" USB port,
it may be possible to connect to a provider without entering the
PIN again even if the system was rebooted.
.Sh HARDWARE
The
.Nm
driver should support any USB device implementing MBIM, including
the following cellular modems:
.Pp
.Bl -bullet -compact
.It
Ericsson H5321gw and N5321gw
.It
Fibocom L831-EAU
.It
Medion Mobile S4222 (MediaTek OEM)
.It
Sierra Wireless EM7345
.It
Sierra Wireless EM7455
.It
Sierra Wireless EM8805
.It
Sierra Wireless MC8305
.El
.Sh SEE ALSO
.Xr intro 4 ,
.Xr netintro 4 ,
.Xr usb 4 ,
.Xr ifconfig 8 ,
.Xr umbctl 8
.Rs
.%T "Universal Serial Bus Communications Class Subclass Specification for Mobile Broadband Interface Model"
.%U http://www.usb.org/developers/docs/devclass_docs/MBIM10Errata1_073013.zip
.Re
.Sh HISTORY
The
.Nm
device driver first appeared in
.Ox 6.0 ,
.Nx 9.0 ,
and
.Fx 15.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm
driver was written by
.An Gerhard Roth Aq Mt gerhard@openbsd.org
and ported from
.Ox
by
.An Pierre Pronchery Aq Mt khorben@defora.org .
.Sh CAVEATS
The
.Nm
driver does not support IPv6.
.Pp
Devices which fail to provide a conforming MBIM implementation will
probably be attached as some other driver, such as
.Xr u3g 4 .
